Method and apparatus for providing posterior or anterior trans-sacral access to spinal vertebrae

Abstract

Methods and apparatus for providing percutaneous access to the human sacral and lumbar vertebrae in alignment with a visualized, trans-sacral axial instrumentation/fusion (TASIF) line in a minimally invasive, low trauma, manner are disclosed. A number of related TASIF methods and surgical tool sets are provided by the present invention that are employed to form a percutaneous pathway from an anterior or posterior skin incision to a respective anterior or posterior target point of a sacral surface. The percutaneous pathway is generally axially aligned with an anterior axial instrumentation/fusion line (AAIFL) or a posterior axial instrumentation/fusion line (PAIFL) extending from the respective anterior or posterior target point through at least one sacral vertebral body and one or more lumbar vertebral body in the cephalad direction and visualized by radiographic or fluoroscopic equipment. The anterior or posterior percutaneous pathway so formed enables introduction of further tools and instruments for boring one or more respective anterior or posterior TASIF bore in the cephalad direction through the one or more vertebral bodies and intervening discs, if present. A single anterior or posterior TASIF bore is preferably aligned axially with the respective visualized AAIFL or PAIFL, and plural anterior or posterior TASIF bores are preferably aligned in parallel with the respective visualized AAIFL or PAIFL. Introduction of spinal implants and instruments is enabled by the provision of the percutaneous pathway in accordance with the present invention and formation of the anterior or posterior TASIF bore(s).

What is claimed is:  
     
       1. A method of providing access to a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the method comprising: 
       making an incision through the patient's skin adjacent to the coccyx aligned with a visualized anterior axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies;  
       providing an elongated guide assembly having guide assembly proximal and distal ends, said guide assembly comprising an elongated tubular member having a tubular member lumen extending between proximal and distal tubular member ends,  
       advancing the guide assembly through the incision to locate the guide assembly distal end against the anterior surface of the sacrum;  
       further advancing the guide assembly distal end along the anterior surface in the cephalad direction under visualization until the guide assembly distal end is at an anterior target point of a selected sacral vertebrae and the guide assembly body is aligned with the visualized anterior axial instrumentation/fusion line and extends percutaneously to the guide assembly proximal end; and  
       advancing the tubular member distal end against the anterior surface at the anterior target point; whereby the tubular member provides a percutaneous tract over or through the tubular member from the incision site to the anterior target point and aligned axially with said visualized anterior axial instrumentation/fusion line.  
     
     
       2. The method of  claim 1 , wherein the step of providing an elongated guide assembly further comprises providing a beveled tip tubular member having a tubular member lumen within a tubular member body extending from a proximal tubular member end to a distal tubular member end as said elongated tubular member, the beveled tip beveled at an angle that is correlated with the angle of the surface of the sacrum at the anterior target point to the visualized anterior axial instrumentation/fusion line. 
     
     
       3. The method of  claim 1 , wherein the step of providing an elongated guide assembly further comprises providing a blunt tip tubular member having a tubular member lumen within a tubular member body extending from a proximal tubular member end to a distal tubular member end as said elongated tubular member. 
     
     
       4. The method of  claim 1 , wherein the step of providing an elongated guide assembly further comprises providing a trocar having a trocar lumen within a stiff trocar body extending from a proximal trocar end to a distal trocar end as said elongated tubular member. 
     
     
       5. The method of  claim 1 , wherein the step of providing an elongated guide assembly further comprises providing a guide sheath having a guide sheath lumen within a flexible guide sheath body extending from a proximal guide sheath end to a distal guide sheath end as said elongated tubular member. 
     
     
       6. The method of  claim 1 , further comprising: 
       providing a guidewire having a guidewire body extending between a guidewire proximal end and a guidewire distal end having a guidewire fixation mechanism for penetrating and affixing to bone at the guidewire distal end;  
       extending the guidewire through said tubular member lumen following removal of the occluder to locate the guidewire distal end at the anterior target point;  
       while maintaining said tubular member aligned axially with the visualized anterior axial instrumentation/fusion line, affixing the guidewire fixation mechanism to bone at the anterior target point; and  
       removing the tubular member while maintaining the guidewire aligned with the visualized anterior axial instrumentation/fusion line,  
       whereby the attached guidewire provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line.  
     
     
       7. The method of  claim 6 , wherein said guidewire is formed with a flexible guidewire body. 
     
     
       8. The method of  claim 6 , wherein said guidewire is formed with a stiff guidewire body. 
     
     
       9. The method of  claim 6 , wherein the guidewire fixation mechanism comprises a distal screw-in tip adapted to be screwed into bone, and the step of affixing the guidewire fixation mechanism to bone at the anterior target point comprises rotating the guidewire body in a proximal section extending proximally from said tubular member lumen to screw said distal screw-in tip into sacral bone. 
     
     
       10. The method of  claim 6 , wherein the guidewire fixation mechanism comprises a distal sharpened tip adapted to be pushed into bone, and the step of affixing the guidewire fixation mechanism to bone at the anterior target point comprises pushing the guidewire body in a proximal section extending proximally from said tubular member lumen distally to push said distal sharpened tip into sacral bone. 
     
     
       11. A method of providing access to a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the method comprising: 
       making an incision through the patient's skin adjacent to the coccyx aligned with a visualized anterior axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies;  
       providing an elongated guide assembly having guide assembly proximal and distal ends, said guide assembly comprising an elongated tubular member having a tubular member lumen extending between proximal and distal tubular member ends and an elongated guidewire having a guidewire body extending between a guidewire proximal end and a guidewire distal end having a guidewire fixation mechanism for penetrating and affixing to bone at the guidewire distal end;  
       inserting the guidewire through said tubular member lumen to locate the guidewire distal end retracted within said tubular member lumen and said guidewire proximal end extending proximally from said tubular member proximal end;  
       advancing the guide assembly through the incision to locate the guide assembly distal end against the anterior surface of the sacrum;  
       further advancing the guide assembly distal end along the anterior surface in the cephalad direction under visualization until the guide assembly distal end is at an anterior target point of a selected sacral vertebrae and the guide assembly body is aligned with the visualized anterior axial instrumentation/fusion line and extends percutaneously to the guide assembly proximal end;  
       extending the guidewire through said tubular member lumen into contact with the sacrum;  
       while maintaining said tubular member aligned axially with the visualized anterior axial instrumentation/fusion line, affixing the guidewire fixation mechanism to sacral bone at the anterior target point; and  
       removing the tubular member while maintaining the guidewire aligned with the visualized anterior axial instrumentation/fusion line,  
       whereby the attached guidewire provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line.  
     
     
       12. The method of  claim 11 , wherein the step of providing an elongated guide assembly further comprises providing a blunt tip tubular member having a tubular member lumen within a tubular member body extending from a proximal tubular member end to a distal tubular member end as said elongated tubular member. 
     
     
       13. The method of  claim 11 , wherein the step of providing an elongated guide assembly further comprises providing a trocar having a trocar lumen within a stiff trocar body extending from a proximal trocar end to a distal trocar end as said elongated tubular member. 
     
     
       14. The method of  claim 11 , herein the step of providing an elongated guide assembly further comprises providing a guide sheath having a guide sheath lumen within a flexible guide sheath body extending from a proximal guide sheath end to a distal guide sheath end as said elongated tubular member. 
     
     
       15. The method of  claim 11 , wherein said guidewire is formed with a flexible guidewire body. 
     
     
       16. The method of  claim 11 , wherein said guidewire is formed with a stiff guidewire body. 
     
     
       17. The method of  claim 11 , wherein the guidewire fixation mechanism comprises a distal screw-in tip adapted to be screwed into sacral bone, and the step of affixing the guidewire fixation mechanism to bone at the anterior target point comprises rotating the guidewire body in a proximal section extending proximally from said tubular member lumen to screw said distal screw-in tip into sacral bone. 
     
     
       18. The method of  claim 11 , wherein the guidewire fixation mechanism comprises a distal sharpened tip adapted to be pushed into sacral bone, and the step of affixing the guidewire fixation mechanism to bone at the anterior target point comprises pushing the guidewire body in a proximal section extending proximally from said tubular member lumen distally to push said distal sharpened tip into sacral bone. 
     
     
       19. The method of  claim 11 , further comprising: 
       dilating the tissue surrounding the guidewire body;  
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends; and  
       inserting said anterior tract sheath through said enlarged anterior tissue tract over said guidewire to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       20. The method of  claim 11 , further comprising: 
       providing a dilatation balloon catheter;  
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends;  
       with the guidewire aligned with the anterior axial instrumentation/fusion line, advancing the dilatation balloon catheter over the guidewire to locate a deflated balloon of the dilatation balloon catheter extending through presacral space;  
       expanding the deflated balloon to an expanded balloon diameter to dilate the presacral tissue between the anterior sacral surface and the skin incision;  
       advancing the enlarged diameter anterior tract sheath lumen over the expanded balloon to position the anterior tract sheath between the anterior target point and the skin incision and in alignment with the anterior axial instrumentation/fusion line; and  
       deflating the balloon and withdrawing the balloon catheter from the anterior tract sheath lumen, whereby the anterior tract sheath lumen provides the anterior, presacral, percutaneous tract through the patient's presacral space.  
     
     
       21. The method of  claim 11 , further comprising: 
       providing a tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the guidewire and extending between proximal and distal dilator body ends;  
       passing the dilator over the guidewire toward the anterior target point to dilate the tissue surrounding the guidewire body; and  
       withdrawing the tissue dilator from the guidewire body upon completion of dilation.  
     
     
       22. The method of  claim 21 , further comprising: 
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends; and  
       inserting said anterior tract sheath through said enlarged anterior tissue tract to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       23. The method of  claim 11 , further comprising: 
       providing a first tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the guidewire and extending between proximal and distal first tissue dilator body ends;  
       providing a second tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the first tissue dilator body and extending between proximal and distal second tissue dilator body ends;  
       passing the first tissue dilator over the guidewire toward the anterior target point to dilate the tissue surrounding the guidewire body;  
       passing the second tissue dilator over first tissue dilator and the guidewire toward the anterior target point to further dilate the tissue surrounding the guidewire body; and  
       withdrawing the first and second tissue dilators from the guidewire body upon completion of dilation.  
     
     
       24. The method of  claim 23 , further comprising: 
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends; and  
       inserting said anterior tract sheath through said enlarged anterior tissue tract to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       25. The method of  claim 11 , further comprising: 
       providing an enlarged diameter tubular anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends and an anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone;  
       inserting said enlarged diameter anterior tract sheath through said enlarged anterior tissue tract over said guidewire to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line; and  
       operating said anterior tract sheath distal fixation mechanism to attach said anterior tract sheath to sacral bone with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       26. The method of  claim 25 , wherein the anterior tract sheath fixation mechanism comprises distal screw threads encircling the distal anterior tract sheath end adapted to be screwed into bone, and the step of affixing the anterior tract sheath distal fixation mechanism to bone at the anterior target point comprises rotating the anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone. 
     
     
       27. The method of  claim 11 , further comprising the step of: 
       dilating the tissue between the skin incision and the anterior target point around the tubular member to provide an enlarged anterior tract through between the skin incision and the anterior target point.  
     
     
       28. The method of  claim 27 , further comprising: 
       providing an enlarged diameter tubular anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends and an anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone;  
       inserting said anterior tract sheath through said enlarged anterior tissue tract to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line; and  
       operating said anterior tract sheath distal fixation mechanism to attach said anterior tract sheath to sacral bone with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       29. The method of  claim 27 , further comprising: 
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends with distal screw threads encircling the distal anterior tract sheath end adapted to be screwed into sacral bone;  
       inserting said enlarged diameter anterior tract sheath through said enlarged anterior tissue tract to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line; and  
       rotating the enlarged diameter anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       30. A method of providing access to a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the method comprising: 
       making an incision through the patient's skin adjacent to the coccyx aligned with a visualized anterior axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies;  
       providing an elongated guide assembly having guide assembly proximal and distal ends, said guide assembly comprising an elongated tubular member having a tubular member lumen extending between proximal and distal tubular member ends, said tubular member having a tubular member fixation mechanism at said distal tubular member end adapted to be fixed to sacral bone and an elongated occluder extending between a proximal occluder end and a distal occluder end that is blunt,  
       inserting said occluder through said tubular member lumen to position said distal occluder end distally protruding from said tubular member fixation mechanism thereby forming a guide assembly distal end that is blunt and diminishes potential tissue penetration;  
       advancing the guide assembly through the incision to locate the guide assembly distal end against the anterior surface of the sacrum;  
       further advancing the guide assembly distal end along the anterior surface in the cephalad direction under visualization until the guide assembly distal end is at an anterior target point of a selected sacral vertebrae and the guide assembly body is aligned with the visualized anterior axial instrumentation/fusion line and extends percutaneously to the guide assembly proximal end;  
       advancing the tubular member distal end over the occluder and against the anterior surface at the anterior target point;  
       fixing said tubular member distal end to sacral bone while axially aligning said tubular member with the visualized anterior axial instrumentation/fusion line; and  
       removing the occluder from the tubular member lumen, whereby the tubular member provides a percutaneous tract over or through the tubular member from the incision site to the anterior target point and aligned axially with said visualized anterior axial instrumentation/fusion line.  
     
     
       31. The method of  claim 30 , wherein the tubular member fixation mechanism comprises a distal threaded tip adapted to be screwed into bone, and the step of affixing the tubular member fixation mechanism to sacral bone at the anterior target point comprises rotating the tubular member in a proximal. section to screw said distal threaded tip into sacral bone. 
     
     
       32. The method of  claim 30 , wherein the tubular member fixation mechanism comprises distal sharpened teeth adapted to be pushed into sacral bone, and the step of affixing the tubular member fixation mechanism to bone at the anterior target point comprises pushing the tubular member distally to push said distal sharpened tip into sacral bone. 
     
     
       33. The method of  claim 30 , further comprising: 
       dilating the tissue surrounding the tubular member body;  
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends; and  
       inserting said anterior tract sheath through said enlarged anterior tissue tract over said tubular member to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       34. The method of  claim 30 , further comprising: 
       providing a dilatation balloon catheter;  
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends;  
       with the tubular member aligned with the anterior axial instrumentation/fusion line, advancing the dilatation balloon catheter over the tubular member to locate a deflated balloon of the dilatation balloon catheter extending through presacral space;  
       expanding the deflated balloon to an expanded balloon diameter to dilate the presacral tissue between the anterior sacral surface and the skin incision;  
       advancing the enlarged diameter anterior tract sheath lumen over the expanded balloon to position the anterior tract sheath between the anterior target point and the skin incision and in alignment with the anterior axial instrumentation/fusion line; and  
       deflating the balloon and withdrawing the balloon catheter from the anterior tract sheath lumen, whereby the anterior tract sheath lumen provides the anterior, presacral, percutaneous tract through the patient's presacral space.  
     
     
       35. The method of  claim 30 , further comprising: 
       providing a tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the tubular member and extending between proximal and distal dilator body ends;  
       passing the dilator over the tubular member toward the anterior target point to dilate the tissue surrounding the tubular member body; and  
       withdrawing the tissue dilator from the tubular member body upon completion of dilation.  
     
     
       36. The method of  claim 35 , further comprising: 
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends; and  
       inserting said anterior tract sheath through said enlarged anterior tissue tract to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       37. The method of  claim 30 , further comprising: 
       providing a first tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the tubular member and extending between proximal and distal first tissue dilator body ends;  
       providing a second tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the first tissue dilator body and extending between proximal and distal second tissue dilator body ends;  
       passing the first tissue dilator over the tubular member toward the anterior target point to dilate the tissue surrounding the tubular member body;  
       passing the second tissue dilator over first tissue dilator and the tubular member toward the anterior target point to further dilate the tissue surrounding the tubular member body; and  
       withdrawing the first and second tissue dilators from the tubular member body upon completion of dilation.  
     
     
       38. The method of  claim 37 , further comprising: 
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends; and  
       inserting said anterior tract sheath through said enlarged anterior tissue tract to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       39. The method of  claim 30 , further comprising: 
       providing an enlarged diameter tubular anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends and an anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone;  
       inserting said enlarged diameter anterior tract sheath through said enlarged anterior tissue tract over said tubular member to position said anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line; and  
       operating said anterior tract sheath distal fixation mechanism to attach said anterior tract sheath to sacral bone with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       40. The method of  claim 39 , wherein the anterior tract sheath fixation mechanism comprises distal screw threads encircling the distal anterior tract sheath end adapted to be screwed into bone, and the step of affixing the anterior tract sheath distal fixation mechanism to bone at the anterior target point comprises rotating the anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone. 
     
     
       41. The method of  claim 30 , further comprising the step of: 
       dilating the tissue between the skin incision and the anterior target point around the tubular member to provide an enlarged anterior tract through between the skin incision and the anterior target point.  
     
     
       42. The method of  claim 41 , further comprising: 
       providing an enlarged diameter tubular anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends and an anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone;  
       inserting said anterior tract sheath through said enlarged anterior tissue tract to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line; and  
       operating said anterior tract sheath distal fixation mechanism to attach said anterior tract sheath to sacral bone with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       43. The method of  claim 41 , further comprising: 
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends with distal screw threads encircling the distal anterior tract sheath end adapted to be screwed into sacral bone;  
       inserting said enlarged diameter anterior tract sheath through said enlarged anterior tissue tract to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line; and  
       rotating the enlarged diameter anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       44. A method of providing access to a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the method comprising: 
       making an incision through the patient's skin adjacent to the coccyx aligned with a visualized anterior axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies;  
       forming a tissue tract percutaneously between the skin incision and an anterior target point of a selected sacral vertebrae aligned with a visualized anterior axial instrumentation/fusion line extending in the cephalad direction though one or more vertebral bodies and intervening discs, if present,  
       providing a boring tool for boring a pilot hole in the cephalad direction through one or more vertebral body and intervening disc, if present;  
       boring a pilot hole with the boring tool in the cephalad direction though the one or more vertebral bodies and intervening discs aligned axially with the visualized anterior axial instrumentation/fusion line;  
       providing a guidewire having a guidewire body extending between a guidewire proximal end and a guidewire distal end having a guidewire fixation mechanism for penetrating and affixing to bone at the guidewire distal end;  
       inserting the guidewire through the tissue tract and the pilot hole; and  
       affixing the guidewire fixation mechanism to vertebral bone at the cephalad end of the pilot hole,  
       whereby the attached guidewire provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line.  
     
     
       45. The method of  claim 44 , wherein said guidewire is formed with a flexible guidewire body. 
     
     
       46. The method of  claim 44 , wherein said guidewire is formed with a stiff guidewire body. 
     
     
       47. The method of  claim 44 , wherein the guidewire fixation mechanism comprises a distal screw-in tip adapted to be screwed into vertebral bone, and the step of affixing the guidewire fixation mechanism to bone at the cephalad end of the pilot hole comprises rotating the guidewire body in a proximal section extending proximally from said tubular member lumen to screw said distal screwin tip into vertebral bone. 
     
     
       48. The method of  claim 44 , wherein the guidewire fixation mechanism comprises a distal sharpened tip adapted to be pushed into vertebral bone, and the step of affixing the guidewire fixation mechanism to vertebral bone at the cephalad end of the pilot hole comprises pushing the guidewire body in a proximal section extending proximally from said tubular member lumen distally to push said distal sharpened tip into vertebral bone. 
     
     
       49. The method of  claim 44 , further comprising: 
       dilating the tissue surrounding the guidewire body outside the pilot hole;  
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends; and  
       inserting said anterior tract sheath through said enlarged anterior tissue tract over said guidewire to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       50. The method of  claim 44 , further comprising: 
       providing a dilatation balloon catheter;  
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends;  
       with the guidewire aligned with the anterior axial instrumentation/fusion line, advancing the dilatation balloon catheter over the guidewire to locate a deflated balloon of the dilatation balloon catheter extending through presacral space;  
       expanding the deflated balloon to an expanded balloon diameter to dilate the presacral tissue between the pilot hole and the skin incision;  
       advancing the enlarged diameter anterior tract sheath lumen over the expanded balloon to position the anterior tract sheath between the anterior target point and the skin incision and in alignment with the anterior axial instrumentation/fusion line; and  
       deflating the balloon and withdrawing the balloon catheter from the anterior tract sheath lumen, whereby the anterior tract sheath lumen provides the anterior, presacral, percutaneous tract through the patient's presacral space.  
     
     
       51. The method of  claim 44 , further comprising: 
       providing a tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the guidewire and extending between proximal and distal dilator body ends;  
       passing the dilator over the guidewire toward the anterior target point to dilate the tissue surrounding the guidewire body; and  
       withdrawing the tissue dilator from the guidewire body upon completion of dilation.  
     
     
       52. The method of  claim 51 , further comprising: 
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends; and  
       inserting said anterior tract sheath through said enlarged anterior tissue tract to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       53. The method of  claim 44 , further comprising: 
       providing a first tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the guidewire and extending between proximal and distal first tissue dilator body ends;  
       providing a second tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the first tissue dilator body and extending between proximal and distal second tissue dilator body ends;  
       passing the first tissue dilator over the guidewire toward the anterior target point to dilate the tissue surrounding the guidewire body;  
       passing the second tissue dilator over first tissue dilator and the guidewire toward the anterior target point to further dilate the tissue surrounding the guidewire body; and  
       withdrawing the first and second tissue dilators from the guidewire body upon completion of dilation.  
     
     
       54. The method of  claim 33 , further comprising: 
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends; and  
       inserting said anterior tract sheath through said enlarged anterior tissue tract to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       55. The method of  claim 44 , further comprising: 
       providing an enlarged diameter tubular anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends and an anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone;  
       inserting said enlarged diameter anterior tract sheath through said enlarged anterior tissue tract over said guidewire to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line; and  
       operating said anterior tract sheath distal fixation mechanism to attach said anterior tract sheath to sacral bone with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       56. The method of  claim 55 , wherein the anterior tract sheath fixation mechanism comprises distal screw threads encircling the distal anterior tract sheath end adapted to be screwed into bone, and the step of affixing the anterior tract sheath distal fixation mechanism to bone at the anterior target point comprises rotating the anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone. 
     
     
       57. The method of  claim 44 , further comprising the step of: 
       dilating the tissue between the skin incision and the anterior target point around the tubular member to provide an enlarged anterior tract through between the skin incision and the anterior target point.  
     
     
       58. The method of  claim 57 , further comprising: 
       providing an enlarged diameter tubular anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends and an anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone;  
       inserting said anterior tract sheath through said enlarged anterior tissue tract to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line; and  
       operating said anterior tract sheath distal fixation mechanism to attach said anterior tract sheath to sacral bone with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       59. The method of  claim 57 , further comprising: 
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between proximal and distal anterior tract sheath ends with distal screw threads encircling the distal anterior tract sheath end adapted to be screwed into sacral bone;  
       inserting said enlarged diameter anterior tract sheath through said enlarged anterior tissue tract to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line; and  
       rotating the enlarged diameter anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone with the anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       60. The method of  claim 44 , further comprising: 
       providing an intermediate anterior tract sheath having a tract sheath lumen extending between proximal and distal intermediate anterior tract sheath ends;  
       after said guidewire is affixed to the anterior target point, inserting said intermediate anterior tract sheath through said enlarged anterior tissue tract over said guidewire to position said distal intermediate anterior tract sheath distal end against the anterior sacrum with the intermediate anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line; and  
       withdrawing said guidewire from the intermediate anterior tract sheath lumen; and wherein:  
       the boring step further comprises:  
       inserting the boring tool through the intermediate anterior tract sheath lumen to the anterior target point;  
       then boring the pilot hole in the cephalad direction through one or more vertebral body and intervening disc, if present, aligned with the visualized anterior axial instrumentation/fusion line; and  
       withdrawing the boring tool.  
     
     
       61. A method of providing access to a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the method comprising: 
       making an incision through the patient's skin adjacent to the coccyx aligned with a visualized anterior axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies;  
       providing an elongated guide assembly having guide assembly proximal and distal ends, said guide assembly comprising an elongated tubular member having a tubular member lumen extending between proximal and distal tubular member ends and an elongated occluder extending between a proximal occluder end and a distal occluder end that is blunt,  
       inserting said occluder through said tubular member lumen to position said distal occluder end at or distally protruding from said distal tubular member end thereby forming a guide assembly distal end that is blunt and diminishes potential tissue penetration;  
       advancing the guide assembly through the incision to locate the guide assembly distal end against the anterior surface of the sacrum;  
       further advancing the guide assembly distal end along the anterior surface in the cephalad direction under visualization until the guide assembly distal end is at an anterior target point of a selected sacral vertebrae and the guide assembly body is aligned with the visualized anterior axial instrumentation/fusion line and extends percutaneously to the guide assembly proximal end;  
       advancing the tubular member distal end over the occluder and against the anterior surface at the anterior target point;  
       removing the occluder from the tubular member lumen;  
       providing a guidewire having a guidewire body extending between a guidewire proximal end and a guidewire distal end having a guidewire fixation mechanism for penetrating and affixing to bone at the guidewire distal end;  
       extending the guidewire through said tubular member lumen following removal of the occluder to locate the guidewire distal end at the anterior target point;  
       while maintaining said tubular member aligned axially with the visualized anterior axial instrumentation/fusion line, affixing the guidewire fixation mechanism to bone at the anterior target point;  
       removing the tubular member while maintaining the guidewire aligned with the visualized anterior axial instrumentation/fusion line;  
       dilating the tissue between the skin incision and the anterior target point around the guidewire to provide an enlarged anterior tissue tract through between the skin incision and the anterior target point;  
       providing an intermediate anterior tract sheath having a tract sheath lumen extending between proximal and distal intermediate anterior tract sheath ends;  
       inserting said intermediate anterior tract sheath through said enlarged anterior tissue tract over said guidewire to position said distal intermediate anterior tract sheath distal end against the anterior sacrum with the intermediate anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line;  
       withdrawing said guidewire from the intermediate anterior tract sheath lumen;  
       providing a boring tool for boring a pilot hole in the cephalad direction through one or more vertebral body and intervening disc, if present;  
       inserting the boring tool through the intermediate anterior tract sheath lumen to the anterior target point, boring a pilot hole in the cephalad direction through one or more vertebral body and intervening disc, if present, aligned with the visualized anterior axial instrumentation/fusion line, and withdrawing the boring tool;  
       inserting the guidewire through the intermediate anterior tract sheath lumen and the pilot hole  
       affixing the guidewire fixation mechanism to vertebral bone at the cephalad end of the pilot hole; and  
       withdrawing the intermediate anterior tract sheath.  
       whereby the attached guidewire provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line.  
     
     
       62. The method of  claim 61 , wherein the step of providing an elongated guide assembly further comprises providing a beveled tip tubular member having a tubular member lumen within a tubular member body extending from a proximal tubular member end to a distal tubular member end as said elongated tubular member, the beveled tip beveled at an angle that is correlated with the angle of the surface of the sacrum at the anterior target point to the visualized anterior axial instrumentation/fusion line. 
     
     
       63. The method of  claim 61 , wherein the step of providing an elongated guide assembly further comprises providing a blunt tip tubular member having a tubular member lumen within a tubular member body extending from a proximal tubular member end to a distal tubular member end as said elongated tubular member. 
     
     
       64. The method of  claim 61 , wherein the step of providing an elongated guide assembly further comprises providing a trocar having a trocar lumen within a stiff trocar body extending from a proximal trocar end to a distal trocar end as said elongated tubular member. 
     
     
       65. The method of  claim 61 , wherein the step of providing an elongated guide assembly further comprises providing a guide sheath having a guide sheath lumen within a flexible guide sheath body extending from a proximal guide sheath end to a distal guide sheath end as said elongated tubular member. 
     
     
       66. The method of  claim 61 , wherein said guidewire is formed with a flexible guidewire body. 
     
     
       67. The method of  claim 61 , wherein said guidewire is formed with a stiff guidewire body. 
     
     
       68. The method of  claim 61 , wherein the guidewire fixation mechanism comprises a distal screw-in tip adapted to be screwed into bone, and the steps of affixing the guidewire fixation mechanism to bone at the anterior target point and the cephalad end of the pilot hole comprises rotating the guidewire body in a proximal section extending proximally from said tubular member lumen to screw said distal screw-in tip into bone. 
     
     
       69. The method of  claim 61 , further comprising the step of: 
       following the removal of the intermediate anterior tract sheath, dilating the tissue between the skin incision and the anterior target point around the guidewire attached to the cephalad end of the pilot hole to provide an enlarged anterior tract through between the skin incision and the anterior target point.  
     
     
       70. The method of  claim 61 , further comprising: 
       following the removal of the intermediate anterior tract sheath, dilating the tissue between the skin incision and the anterior target point around the guidewire attached to the cephalad end of the pilot hole to provide an enlarged anterior tract through between the skin incision and the anterior target point;  
       dilating the tissue between the skin incision and the anterior target point around the guidewire to provide an enlarged anterior tissue tract through between the skin incision and the anterior target point;  
       providing an enlarged diameter tubular enlarged diameter anterior tract sheath having a tract sheath lumen extending between enlarged diameter anterior tract sheath proximal and distal ends and an enlarged diameter anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone;  
       inserting said enlarged diameter anterior tract sheath through said enlarged anterior tissue tract over said guidewire to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line;  
       operating said enlarged diameter anterior tract sheath distal fixation mechanism to attach said enlarged diameter anterior tract sheath to sacral bone with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       71. The method of  claim 70 , wherein the enlarged diameter anterior tract sheath fixation mechanism comprises distal screw threads encircling the enlarged diameter anterior tract sheath distal end adapted to be screwed into bone, and the step of affixing the enlarged diameter anterior tract sheath fixation mechanism to bone at the anterior target point comprises rotating the enlarged diameter anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone. 
     
     
       72. The method of  claim 61 , further comprising: 
       following the removal of the intermediate anterior tract sheath, dilating the tissue between the skin incision and the anterior target point around the guidewire attached to the cephalad end of the pilot hole to provide an enlarged anterior tract through between the skin incision and the anterior target point;  
       providing an enlarged diameter anterior tract sheath having a tract sheath lumen extending between enlarged diameter anterior tract sheath proximal and distal ends;  
       inserting said enlarged diameter anterior tract sheath through said enlarged anterior tissue tract over said guidewire to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       73. The method of  claim 72 , wherein the dilating step further comprises: 
       providing a tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the guidewire and extending between proximal and distal dilator body ends;  
       passing the dilator over the guidewire toward the anterior target point to dilate the tissue surrounding the guidewire body; and  
       withdrawing the tissue dilator from the guidewire body upon completion of dilation.  
     
     
       74. The method of  claim 73 , wherein: 
       the step of providing a tissue dilator comprises providing a plurality of tissue dilators each having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the guidewire and extending between proximal and distal dilator body ends; and  
       the steps of passing and withdrawing the tissue dilator, comprises repeatedly passing tissue dilators of increasing dilation diameter to progressively dilate tissue between the skin incision and the anterior target point.  
     
     
       75. The method of  claim 73 , further comprising: 
       providing an enlarged diameter tubular enlarged diameter anterior tract sheath having a tract sheath lumen extending between enlarged diameter anterior tract sheath proximal and distal ends; and  
       inserting said enlarged diameter anterior tract sheath through said enlarged anterior tissue tract over the dilator to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       76. The method of  claim 72 , wherein the dilating step further comprises: 
       providing a dilatation balloon catheter and tubular enlarged diameter anterior tract sheath;  
       with the guidewire aligned with the anterior axial instrumentation/fusion line, advancing the dilatation balloon catheter over the guidewire to locate a deflated balloon of the dilatation balloon catheter extending through presacral space;  
       expanding the deflated balloon to an expanded balloon diameter to dilate the presacral tissue between the anterior target point and the skin incision; and  
       deflating and withdrawing the balloon catheter from the enlarged diameter anterior tract sheath lumen, whereby the enlarged diameter anterior tract sheath lumen provides the anterior, presacral, percutaneous tract through the patient's presacral space.  
     
     
       77. The method of  claim 76 , further comprising: 
       providing an enlarged diameter tubular enlarged diameter anterior tract sheath having a tract sheath lumen extending between enlarged diameter anterior tract sheath proximal and distal ends; and  
       inserting said enlarged diameter anterior tract sheath through said enlarged anterior tissue tract over the expanded balloon to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       78. The method of  claim 76 , further comprising: 
       providing an enlarged diameter tubular enlarged diameter anterior tract sheath having a tract sheath lumen extending between enlarged diameter anterior tract sheath proximal and distal ends and an enlarged diameter anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone;  
       inserting said enlarged diameter anterior tract sheath through said enlarged anterior tissue tract over the expanded balloon to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line;  
       operating said enlarged diameter anterior tract sheath distal fixation mechanism to attach said enlarged diameter anterior tract sheath to sacral bone with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line; and  
       deflating the balloon and withdrawing the balloon catheter and guidewire from the enlarged diameter anterior tract sheath lumen.  
     
     
       79. The method of  claim 78 , wherein the enlarged diameter anterior tract sheath fixation mechanism comprises distal screw threads encircling the enlarged diameter anterior tract sheath distal end adapted to be screwed into bone, and the operating step further comprises: 
       rotating the enlarged diameter anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line.  
     
     
       80. A method of providing access to a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the method comprising: 
       from a skin incision adjacent to the coccyx, forming an anterior, presacral, percutaneous tract through the patient's presacral space to access an anterior presacral position of a sacral vertebra in alignment with a visualized, anterior axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies by:  
       expanding a percutaneous pathway through the patient's presacral space;  
       providing a tubular anterior tract sheath having a tract sheath axis and tract sheath lumen extending between proximal and distal tract sheath lumen ends; and  
       advancing the anterior tract sheath distal end to said anterior presacral position with said tract sheath axis aligned axially with a sacral end of said visualized, anterior axial instrumentation/fusion line to form the anterior, presacral, percutaneous tract through the tubular anterior tract sheath aligned with the visualized anterior axial instrumentation/fusion line to provide working space and exposure of the anterior sacrum.  
     
     
       81. A method of providing access to a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the method comprising: 
       from a skin incision adjacent to the coccyx, forming an anterior, presacral, percutaneous tract through the patient's presacral space to access an anterior presacral position of a sacral vertebra in alignment with a visualized, anterior axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies by:  
       expanding a percutaneous pathway through the patient's presacral space;  
       providing an elongated guide member having a guide member axis extending between proximal and distal guide member ends and a guide member fixation mechanism at said guide member distal end;  
       advancing the guide member distal end to said anterior presacral position with said guide member axis aligned axially with a sacral end of said visualized, anterior axial instrumentation/fusion line; and  
       fixing the guide member fixation mechanism to sacral bone at the anterior presacral position to form the anterior, presacral, percutaneous tract over the guide member aligned with the visualized anterior axial instrumentation/fusion line to provide working space and exposure of the anterior sacrum.  
     
     
       82. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       guide means operable from a skin incision through a patient's skin and exposing a posterior, presacral position of a sacral vertebra in alignment with a visualized, curved, posterior axial instrumentation/fusion line extending in said axial aspect initially laterally through the sacral vertebra and then following the curvature of the spine through a series of adjacent cephalad vertebral bodies for accessing a posterior sacral position of a sacral vertebra that is aligned with the visualized, trans-sacral axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies; and  
       tract means defining a percutaneous tract having a tract axis aligned with said visualized, trans-sacral axial instrumentation/fusion line and extending from the skin incision to the accessed sacral position to facilitate surgical procedures aligned with said visualized, trans-sacral axial instrumentation/fusion line;  
       wherein the tract means comprises a tubular posterior tract sheath forming a posterior percutaneous tract through the patient's presacral space to access the posterior presacral position of a sacral vertebra in alignment with the visualized, anterior axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies to enable boring a curved posterior axial bore extending along said posterior axial instrumentation/fusion line cephalad through the vertebral bodies of said series of adjacent vertebrae and any intervening spinal discs;  
       wherein the tubular posterior tract sheath has a tract sheath lumen extending between proximal and distal posterior tract sheath ends and a posterior tract sheath distal fixation mechanism adapted to attach said posterior tract sheath distal end to sacral bone with the posterior tract sheath lumen aligned axially with the visualized posterior axial instrumentation/fusion line;  
       wherein the posterior tract sheath fixation mechanism comprises distal screw threads encircling the tract sheath distal end adapted to be screwed into sacral bone.  
     
     
       83. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       guide means operable from a skin incision through a patient's skin and exposing a posterior, presacral position of a sacral vertebra in alignment with a visualized, curved, posterior axial instrumentation/fusion line extending in said axial aspect initially laterally through the sacral vertebra and then following the curvature of the spine through a series of adjacent cephalad vertebral bodies for accessing a posterior sacral position of a sacral vertebra that is aligned with the visualized, trans-sacral axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies;  
       tract means defining a percutaneous tract having a tract axis aligned with said visualized, trans-sacral axial instrumentation/fusion line and extending from the skin incision to the accessed sacral position to facilitate surgical procedures aligned with said visualized, trans-sacral axial instrumentation/fusion line; and  
       means for drilling a pilot hole of a first diameter from said posterior presacral position along said axial instrumentation/fusion line within and axially through said series of vertebral bodies and intervening spinal discs to a cephalad pilot hole end within a vertebral body.  
     
     
       84. The system of  claim 83 , wherein the guide means comprises a guidewire having a guidewire body extending between a guidewire proximal end and a guidewire distal end having a guidewire fixation mechanism at the guidewire distal end adapted to be advanced into the pilot hole, affixed to vertebral bone at the cephalad end of the pilot hole, and aligned axially with the axial instrumentation/fusion line. 
     
     
       85. The system of  claim 84 , wherein the guide means comprises a guidewire having a guidewire body extending between a guidewire proximal end and-a guidewire distal end having a guidewire fixation mechanism at the guidewire distal end adapted to be advanced to the posterior position, affixed to vertebral bone, and aligned axially with the axial instrumentation/fusion line. 
     
     
       86. The system of  claim 83 , wherein the tract means comprises a tubular posterior tract sheath forming a posterior percutaneous tract through the patient's presacral space to access the posterior presacral position of a sacral vertebra in alignment with the visualized, anterior axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies to enable boring a curved posterior axial bore extending along said posterior axial instrumentation/fusion line cephalad through the vertebral bodies of said series of adjacent vertebrae and any intervening spinal discs. 
     
     
       87. The system of  claim 86 , wherein the tubular posterior tract sheath has a tract sheath lumen extending between proximal and distal posterior tract sheath ends and a posterior tract sheath distal fixation mechanism adapted to attach said posterior tract sheath distal end to sacral bone with the posterior tract sheath lumen aligned axially with the visualized posterior axial instrumentation/fusion line. 
     
     
       88. The system of  claim 87 , wherein the posterior tract sheath fixation mechanism comprises distal screw threads encircling the tract sheath distal end adapted to be screwed into sacral bone. 
     
     
       89. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       a tubular member having a tubular member body extending between a tubular member body proximal end and a tubular member body distal end enclosing a tubular-member lumen and having a blunt tip at the tubular member body distal end, the tubular member adapted to be advanced through an incision made through the patient's skin adjacent to the coccyx and along the anterior surface of the sacrum under visualization until the blunt tip is at an anterior target point of a selected sacral vertebrae and the tubular member body is aligned with a visualized anterior axial instrumentation/fusion line extending in the cephalad direction through the series of adjacent vertebrae and extends percutaneously from the proximal tubular member end located outside the incision; and  
       a guidewire extending between guidewire proximal and distal ends and having a guidewire distal fixation mechanism at the guidewire distal end sized to be fitted through the tubular member lumen to position the distal fixation mechanism at the anterior target point with the guidewire proximal end extending out of the tubular member lumen to manipulation of the guidewire to fix the distal fixation mechanism to the sacrum, whereby the tubular member can be withdrawn over the guidewire, leaving the guidewire attached to the anterior target point and extending through the presacral space and percutaneously in alignment with the anterior axial instrumentation/fusion line, whereby the attached guidewire provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line.  
     
     
       90. The system of  claim 89 , further comprising a beveled-tip tract sheath having a beveled-tip sheath lumen and diameter extending between a beveled-tip sheath proximal end and distal bone engaging end, the beveled-tip sheath lumen adapted to receive the guidewire to enable the-beveled-tip sheath lumen to be inserted over the guidewire proximal end and through the presacral space in alignment with the visualized, anterior axial instrumentation/fusion line and the alignment of the distal bone engaging end of the beveled-tip sheath against the sacrum providing an anterior, presacral, percutaneous tract through the patient's presacral space to access the anterior presacral position of a sacral vertebra in alignment with the visualized, anterior axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies. 
     
     
       91. The system of  claim 89 , further comprising means for drilling a pilot hole of a first diameter from said anterior presacral position along the visualized, anterior axial instrumentation/fusion line within and axially through said series of vertebral bodies and intervening spinal discs to a cephalad pilot hole end within a vertebral body. 
     
     
       92. The system of  claim 91 , further comprising: 
       an intermediate anterior tract sheath having a tract sheath lumen extending between proximal and distal intermediate anterior tract sheath ends adapted to be inserted through said anterior tissue tract over said guidewire to position said distal intermediate anterior tract sheath distal end against the anterior sacrum with the intermediate anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line; and  
       a boring tool to bore a pilot hole in the cephalad direction through one or more vertebral body and intervening disc when inserted and advanced through the intermediate anterior tract sheath lumen to the anterior target point, whereby a pilot hole is bored in the cephalad direction through one or more vertebral body and intervening disc, if present, aligned with the visualized anterior axial instrumentation/fusion line.  
     
     
       93. The system of  claim 89 , further comprising a dilator adapted to dilate tissue surrounding the elongated guidewire to form an enlarged percutaneous tract that is aligned with the visualized, anterior axial instrumentation/fusion line. 
     
     
       94. The system of  claim 93 , further comprising an enlarged diameter tubular enlarged diameter anterior tract sheath having a tract sheath lumen extending between enlarged diameter anterior tract sheath proximal and distal ends and an enlarged diameter anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone, said enlarged diameter anterior tract sheath sized in sheath lumen diameter to be advanced through the dilated presacral space to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line, whereupon said enlarged diameter anterior tract sheath distal fixation mechanism is operable to attach said enlarged diameter anterior tract sheath to sacral bone with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized, anterior axial instrumentation/fusion line, whereby the attached enlarged diameter anterior tract sheath lumen provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line. 
     
     
       95. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       a tubular member having a tubular member body extending between a tubular member body proximal end and a tubular member body distal end enclosing a tubular member lumen and having a blunt tip at the tubular member body distal end, the tubular member adapted to be advanced through an incision made through the patient's skin adjacent to the coccyx and along the anterior surface of the sacrum under visualization until the blunt tip is at an anterior target point of a selected sacral vertebrae and the tubular member body is aligned with a visualized anterior axial instrumentation/fusion line extending in the cephalad direction through the series of adjacent vertebrae and extends percutaneously from the proximal tubular member end located outside the incision;  
       a guidewire extending between guidewire proximal and distal ends and having a guidewire distal fixation mechanism at the guidewire distal end sized to be fitted through the tubular member lumen to position the distal fixation mechanism at the anterior target point with the guidewire proximal end extending out of the tubular member lumen to manipulation of the guidewire to fix the distal fixation mechanism to the sacrum, whereby the tubular member can be withdrawn over the guidewire, leaving the guidewire attached to the anterior target point and extending through the presacral space and percutaneously in alignment with the anterior axial instrumentation/fusion line, whereby the attached guidewire provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line; and  
       a threaded-tip tract sheath having a threaded-tip sheath lumen and diameter and a threaded sheath proximal end and a threaded sheath distal bone engaging end, the thread-tipped sheath lumen adapted to receive the guidewire to enable the thread-tipped sheath lumen to be inserted over the guidewire proximal end and through the presacral space in alignment with the visualized anterior axial instrumentation/fusion line and the engagement of the distal bone engaging end of the thread-tipped sheath into the sacrum providing an anterior, presacral, percutaneous tract through the patient's presacral space to access the anterior presacral position of a sacral vertebra in alignment with the visualized, straight axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies.  
     
     
       96. The system of  claim 95 , further comprising a dilator adapted to dilate tissue surrounding the elongated guidewire to form an enlarged percutaneous tract that is aligned with the visualized, anterior axial instrumentation/fusion line. 
     
     
       97. The system of  claim 96 , further comprising an enlarged diameter tubular enlarged diameter anterior tract sheath having a tract sheath lumen extending between enlarged diameter anterior tract sheath proximal and distal ends and an enlarged diameter anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone, said enlarged diameter anterior tract sheath sized in sheath lumen diameter to be advanced through the dilated presacral space to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line, whereupon said enlarged diameter anterior tract sheath distal fixation mechanism is operable to attach said enlarged diameter anterior tract sheath to sacral bone with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized, anterior axial instrumentation/fusion line, whereby the attached enlarged diameter anterior tract sheath lumen provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line. 
     
     
       98. The system of  claim 97 , wherein the enlarged diameter anterior tract sheath fixation mechanism comprises distal screw threads encircling the enlarged diameter anterior tract sheath distal end adapted to be screwed into bone at the anterior target point by rotating the enlarged diameter anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone. 
     
     
       99. The system of  claim 96 , wherein the dilator further comprises: 
       a first tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the guidewire and extending between proximal and distal first tissue dilator body ends, the first tissue dilator is adapted to be advanced over the guidewire toward the anterior target point to dilate the tissue surrounding the guidewire body; and  
       a second tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the first tissue dilator body and extending between proximal and distal second tissue dilator body ends, the second tissue dilator adapted to be advanced over first tissue dilator and the guidewire toward the anterior target point to further dilate the tissue surrounding the guidewire body.  
     
     
       100. The system of  claim 96 , wherein the dilator further comprises: 
       a dilatation balloon catheter having an expandable balloon and a balloon catheter lumen extending between balloon catheter proximal and distal ends, the dilatation balloon catheter adapted to be advanced over the guidewire within the catheter lumen to locate the deflated balloon of the dilatation balloon catheter extending through presacral space; and  
       means for expanding the deflated balloon to an expanded balloon diameter to dilate the presacral tissue between the anterior target point and the skin incision and deflating and withdrawing the balloon catheter from the enlarged diameter anterior tract sheath lumen, whereby the enlarged diameter anterior tract sheath lumen provides the anterior, presacral, percutaneous tract through the patient's presacral space.  
     
     
       101. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       a tubular member having a tubular member body extending between a tubular member body proximal end and a tubular member body distal end enclosing a tubular member lumen and having a blunt tip at the tubular member body distal end, the tubular member adapted to be advanced through an incision made through the patient's skin adjacent to the coccyx and along the anterior surface of the sacrum under visualization until the blunt tip is at an anterior target point of a selected sacral vertebrae and the tubular member body is aligned with a visualized anterior axial instrumentation/fusion line extending in the cephalad direction through the series of adjacent vertebrae and extends percutaneously from the proximal tubular member end located outside the incision;  
       a guidewire extending between guidewire proximal and distal ends and having a guidewire distal fixation mechanism at the guidewire distal end sized to be fitted through the tubular member lumen to position the distal fixation mechanism at the anterior target point with the guidewire proximal end extending out of the tubular member lumen to manipulation of the guidewire to fix the distal fixation mechanism to the sacrum, whereby the tubular member can be withdrawn over the guidewire, leaving the guidewire attached to the anterior target point and extending through the presacral space and percutaneously in alignment with the anterior axial instrumentation/fusion line, whereby the attached guidewire provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line;  
       a dilator adapted to dilate tissue surrounding the elongated guidewire to form an enlarged percutaneous tract that is aligned with the visualized, anterior axial instrumentation/fusion line; and  
       an enlarged diameter tubular enlarged diameter anterior tract sheath having a tract sheath lumen extending between enlarged diameter anterior tract sheath proximal and distal ends and an enlarged diameter anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone, said enlarged diameter anterior tract sheath sized in sheath lumen diameter to be advanced through the dilated presacral space to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line, whereupon said enlarged diameter anterior tract sheath distal fixation mechanism is operable to attach said enlarged diameter anterior tract sheath to sacral bone with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized, anterior axial instrumentation/fusion line, whereby the attached enlarged diameter anterior tract sheath lumen provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line;  
       wherein the enlarged diameter anterior tract sheath fixation mechanism comprises distal screw threads encircling the enlarged diameter anterior tract sheath distal end adapted to be screwed into bone at the anterior target point by rotating the enlarged diameter anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone.  
     
     
       102. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       a tubular member having a tubular member body extending between a tubular member body proximal end and a tubular member body distal end enclosing a tubular member lumen and having a blunt tip at the tubular member body distal end, the tubular member adapted to be advanced through an incision made through the patient's skin adjacent to the coccyx and along the anterior surface of the sacrum under visualization until the blunt tip is at an anterior target point of a selected sacral vertebrae and the tubular member body is aligned with a visualized anterior axial instrumentation/fusion line extending in the cephalad direction through the series of adjacent vertebrae and extends percutaneously from the proximal tubular member end located outside the incision;  
       a guidewire extending between guidewire proximal and distal ends and having a guidewire distal fixation mechanism at the guidewire distal end sized to be fitted through the tubular member lumen to position the distal fixation mechanism at the anterior target point with the guidewire proximal end extending out of the tubular member lumen to manipulation of the guidewire to fix the distal fixation mechanism to the sacrum, whereby the tubular member can be withdrawn over the guidewire, leaving the guidewire attached to the anterior target point and extending through the presacral space and percutaneously in alignment with the anterior axial instrumentation/fusion line, whereby the attached guidewire provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line; and  
       a dilator adapted to dilate tissue surrounding the elongated guidewire to form an enlarged percutaneous tract that is aligned with the visualized, anterior axial instrumentation/fusion line;  
       wherein the dilator further comprises:  
       a first tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the guidewire and extending between proximal and distal first tissue dilator body ends, the first tissue dilator is adapted to be advanced over the guidewire toward the anterior target point to dilate the tissue surrounding the guidewire body; and  
       a second tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the first tissue dilator body and extending between proximal and distal second tissue dilator body ends, the second tissue dilator adapted to be advanced over first tissue dilator and the guidewire toward the anterior target point to further dilate the tissue surrounding the guidewire body.  
     
     
       103. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       a tubular member having a tubular member body extending between a tubular member body proximal end and a tubular member body distal end enclosing a tubular member lumen and having a blunt tip at the tubular member body distal end, the tubular member adapted to be advanced through an incision made through the patient's skin adjacent to the coccyx and along the anterior surface of the sacrum under visualization until the blunt tip is at an anterior target point of a selected sacral vertebrae and the tubular member body is aligned with a visualized anterior axial instrumentation/fusion line extending in the cephalad direction through the series of adjacent vertebrae and extends percutaneously from the proximal tubular member end located outside the incision;  
       a guidewire extending between guidewire proximal and distal ends and having a guidewire distal fixation mechanism at the guidewire distal end sized to be fitted through the tubular member lumen to position the distal fixation mechanism at the anterior target point with the guidewire proximal end extending out of the tubular member lumen to manipulation of the guidewire to fix the distal fixation mechanism to the sacrum, whereby the tubular member can be withdrawn over the guidewire, leaving the guidewire attached to the anterior target point and extending through the presacral space and percutaneously in alignment with the anterior axial instrumentation/fusion line, whereby the attached guidewire provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line; and  
       a dilator adapted to dilate tissue surrounding the elongated guidewire to form an enlarged percutaneous tract that is aligned with the visualized, anterior axial instrumentation/fusion line;  
       wherein the dilator further comprises:  
       a dilatation balloon catheter having an expandable balloon and a balloon catheter lumen extending between balloon catheter proximal and distal ends, the dilatation balloon catheter adapted to be advanced over the guidewire within the catheter lumen to locate the deflated balloon of the dilatation balloon catheter extending through presacral space; and  
       means for expanding the deflated balloon to an expanded balloon diameter to dilate the presacral tissue between the anterior target point and the skin incision and deflating and withdrawing the balloon catheter from the enlarged diameter anterior tract sheath lumen, whereby the enlarged diameter anterior tract sheath lumen provides the anterior, presacral, percutaneous tract through the patient's presacral space.  
     
     
       104. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       an elongated occluder extending between a proximal occluder end and a distal, blunt-tip, occluder end;  
       a tubular member having a tubular member body extending between a tubular member body proximal end and a tubular member body distal end enclosing a tubular member lumen and having a tubular member distal fixation mechanism at the tubular member body distal end, the occluder adapted and sized to be inserted through the tubular member lumen to form a guide assembly with the distal blunt-tip occluder end projecting distally from the tubular member distal fixation mechanism thereby providing a guide assembly distal end with the tubular member distal fixation mechanism retracted to prevent catching on body tissue, the guide assembly adapted to be advanced through an incision made through the patient's skin adjacent to the coccyx aligned with a visualized, anterior axial instrumentation/fusion line and along the anterior surface of the sacrum under visualization until the blunt tip is at an anterior target point of a selected sacral vertebrae and the tubular member body is aligned with the visualized, anterior axial instrumentation/fusion line and extends percutaneously from the proximal tubular member end located outside the incision,  
       whereby the tubular member is adapted to be advanced distally past the distal, blunt tip, occluder end and fixed to sacral bone enabling retention of the tubular member in axial alignment with the visualized, anterior axial instrumentation/fusion line, whereby the attached tubular member provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line.  
     
     
       105. The system of  claim 104 , further comprising a dilator adapted to dilate tissue surrounding the elongated tubular member to form an enlarged percutaneous tract that is aligned with the visualized, anterior axial instrumentation/fusion line. 
     
     
       106. The system of  claim 105 , further comprising an enlarged diameter tubular enlarged diameter anterior tract sheath having a tract sheath lumen extending between enlarged diameter anterior tract sheath proximal and distal ends and an enlarged diameter anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone, said enlarged diameter anterior tract sheath sized in sheath lumen diameter to be advanced through the dilated presacral space to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line, whereupon said enlarged diameter anterior tract sheath distal fixation mechanism is operable to attach said enlarged diameter anterior tract sheath to sacral bone with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized, anterior axial instrumentation/fusion line. 
     
     
       107. The system of  claim 105 , wherein the dilator further comprises: 
       a first tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the tubular member and extending between proximal and distal first tissue dilator body ends, the first tissue dilator is adapted to be advanced over the tubular member toward the anterior target point to dilate the tissue surrounding the tubular member body; and  
       a second tissue dilator having a dilator body of a dilation diameter and a dilator lumen having a dilator lumen diameter sized to receive the first tissue dilator body and extending between proximal and distal second tissue dilator body ends, the second tissue dilator adapted to be advanced over first tissue dilator and the tubular member toward the anterior target point to further dilate the tissue surrounding the tubular member body.  
     
     
       108. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       an elongated occluder extending between a proximal occluder end and a distal, blunt-tip, occluder end;  
       a tubular member having a tubular member body extending between a tubular member body proximal end and a tubular member body distal end enclosing a tubular member lumen and having a tubular member distal fixation mechanism at the tubular member body distal end, the occluder adapted and sized to be inserted through the tubular member lumen to form a guide assembly with the distal blunt-tip occluder end projecting distally from the tubular member distal fixation mechanism thereby providing a guide assembly distal end with the tubular member distal fixation mechanism retracted to prevent catching on body tissue, the guide assembly adapted to be advanced through an incision made through the patient's skin adjacent to the coccyx aligned with a visualized, anterior axial instrumentation/fusion line and along the anterior surface of the sacrum under visualization until the blunt tip is at an anterior target point of a selected sacral vertebrae and the tubular member body is aligned with the visualized, anterior axial instrumentation/fusion line and extends percutaneously from the proximal tubular member end located outside the incision, whereby the tubular member is adapted to be advanced distally past the distal, blunt tip, occluder end and fixed to sacral bone enabling retention of the tubular member in axial alignment with the visualized, anterior axial instrumentation/fusion line, whereby the attached tubular member provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line; and  
       a threaded-tip tract sheath having a threaded-tip sheath lumen and diameter and a threaded sheath proximal end and a threaded sheath distal bone engaging end, the thread-tipped sheath lumen adapted to receive the tubular member to enable the thread-tipped sheath lumen to be inserted over the tubular member proximal end and through the presacral space in alignment with the visualized anterior axial instrumentation/fusion line and the engagement of the distal bone engaging end of the thread-tipped sheath into the sacrum providing an anterior, presacral, percutaneous tract through the patient's presacral space to access the anterior presacral position of a sacral vertebra in alignment with the visualized, straight axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies.  
     
     
       109. The system of  claim 108 , further comprising a beveled-tip tract sheath having a beveled-tip sheath lumen and diameter extending between a beveled-tip sheath proximal end and distal bone engaging end, the beveled-tip sheath lumen adapted to receive the tubular member to enable the beveled-tip sheath lumen to be inserted over the tubular member proximal end and through the presacral space in alignment with the visualized, anterior axial instrumentation/fusion line and the alignment of the distal bone engaging end of the beveled-tip sheath against the sacrum providing an anterior, presacral, percutaneous tract through the patient's presacral space to access the anterior presacral position of a sacral vertebra in alignment with the visualized, anterior axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies. 
     
     
       110. The system of  claim 108 , further comprising a dilator adapted to dilate tissue surrounding the elongated tubular member to form an enlarged percutaneous tract that is aligned with the visualized, anterior axial instrumentation/fusion line. 
     
     
       111. The system of  claim 110 , further comprising an enlarged diameter tubular enlarged diameter anterior tract sheath having a tract sheath lumen extending between enlarged diameter anterior tract sheath proximal and distal ends and an enlarged diameter anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone, said enlarged diameter anterior tract sheath sized in sheath lumen diameter to be advanced through the dilated presacral space to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line, whereupon said enlarged diameter anterior tract sheath distal fixation mechanism is operable to attach said enlarged diameter anterior tract sheath to sacral bone with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized, anterior axial instrumentation/fusion line. 
     
     
       112. The system of  claim 111 , wherein the enlarged diameter anterior tract sheath fixation mechanism comprises distal screw threads encircling the enlarged diameter anterior tract sheath distal end adapted to be screwed into bone at the anterior target point by rotating the enlarged diameter anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone. 
     
     
       113. The system of  claim 110 , wherein the dilator further comprises: 
       a dilatation balloon catheter having an expandable balloon and a balloon catheter lumen extending between balloon catheter proximal and distal ends, the dilatation balloon catheter adapted to be advanced over the tubular member within the catheter lumen to locate the deflated balloon of the dilatation balloon catheter extending through presacral space; and  
       means for expanding the deflated balloon to an expanded balloon diameter to dilate the presacral tissue between the anterior target point and the skin incision and deflating and withdrawing the balloon catheter from the enlarged diameter anterior tract sheath lumen, whereby the enlarged diameter anterior tract sheath lumen provides the anterior, presacral, percutaneous tract through the patient's presacral space.  
     
     
       114. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       an elongated occluder extending between a proximal occluder end and a distal, blunt-tip, occluder end;  
       a tubular member having a tubular member body extending between a tubular member body proximal end and a tubular member body distal end enclosing a tubular member lumen and having a tubular member distal fixation mechanism at the tubular member body distal end, the occluder adapted and sized to be inserted through the tubular member lumen to form a guide assembly with the distal blunt-tip occluder end projecting distally from the tubular member distal fixation mechanism thereby providing a guide assembly distal end with the tubular member distal fixation mechanism retracted to prevent catching on body tissue, the guide assembly adapted to be advanced through an incision made through the patient's skin adjacent to the coccyx aligned with a visualized, anterior axial instrumentation/fusion line and along the anterior surface of the sacrum under visualization until the blunt tip is at an anterior target point of a selected sacral vertebrae and the tubular member body is aligned with the visualized, anterior axial instrumentation/fusion line and extends percutaneously from the proximal tubular member end located outside the incision, whereby the tubular member is adapted to be advanced distally past the distal, blunt tip, occluder end and fixed to sacral bone enabling retention of the tubular member in axial alignment with the visualized, anterior axial instrumentation/fusion line, whereby the attached tubular member provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line; and  
       a beveled-tip tract sheath having a beveled-tip sheath lumen and diameter extending between a beveled-tip sheath proximal end and distal bone engaging end, the beveled-tip sheath lumen adapted to receive the tubular member to enable the beveled-tip sheath lumen to be inserted over the tubular member proximal end and through the presacral space in alignment with the visualized, anterior axial instrumentation/fusion line and the alignment of the distal bone engaging end of the beveled-tip sheath against the sacrum providing an anterior, presacral, percutaneous tract through the patient's presacral space to access the anterior presacral position of a sacral vertebra in alignment with the visualized, anterior axial instrumentation/fusion line extending in said axial aspect through the series of adjacent vertebral bodies.  
     
     
       115. The system of  claim 114 , further comprising a dilator adapted to dilate tissue surrounding the elongated tubular member to form an enlarged percutaneous tract that is aligned with the visualized, anterior axial instrumentation/fusion line. 
     
     
       116. The system of  claim 115 , further comprising an enlarged diameter tubular enlarged diameter anterior tract sheath having a tract sheath lumen extending between enlarged diameter anterior tract sheath proximal and distal ends and an enlarged diameter anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone, said enlarged diameter anterior tract sheath sized in sheath lumen diameter to be advanced through the dilated presacral space to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line, whereupon said enlarged diameter anterior tract sheath distal fixation mechanism is operable to attach said enlarged diameter anterior tract sheath to sacral bone with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized, anterior axial instrumentation/fusion line. 
     
     
       117. The system of  claim 116  wherein the enlarged diameter anterior tract sheath fixation mechanism comprises distal screw threads encircling the enlarged diameter anterior tract sheath distal end adapted to be screwed into bone at the anterior target point by rotating the enlarged diameter anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone. 
     
     
       118. The system of  claim 115 , wherein the dilator further comprises: 
       a dilatation balloon catheter having an expandable balloon and a balloon catheter lumen extending between balloon catheter proximal and distal ends, the dilatation balloon catheter adapted to be advanced over the tubular member within the catheter lumen to locate the deflated balloon of the dilatation balloon catheter extending through presacral space; and  
       means for expanding the deflated balloon to an expanded balloon diameter to dilate the presacral tissue between the anterior target point and the skin incision and deflating and withdrawing the balloon catheter from the enlarged diameter anterior tract sheath lumen, whereby the enlarged diameter anterior tract sheath lumen provides the anterior presacral, percutaneous tract through the patient's presacral space.  
     
     
       119. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       an elongated occluder extending between a proximal occluder end and a distal, blunt-tip, occluder end;  
       a tubular member having a tubular member body extending between a tubular member body proximal end and a tubular member body distal end enclosing a tubular member lumen and having a tubular member distal fixation mechanism at the tubular member body distal end, the occluder adapted and sized to be inserted through the tubular member lumen to form a guide assembly with the distal blunt-tip occluder end projecting distally from the tubular member distal fixation mechanism thereby providing a guide assembly distal end with the tubular member distal fixation mechanism retracted to prevent catching on body tissue, the guide assembly adapted to be advanced through an incision made through the patient's skin adjacent to the coccyx aligned with a visualized, anterior axial instrumentation/fusion line and along the anterior surface of the sacrum under visualization until the blunt tip is at an anterior target point of a selected sacral vertebrae and the tubular member body is aligned with the visualized, anterior axial instrumentation/fusion line and extends percutaneously from the proximal tubular member end located outside the incision, whereby the tubular member is adapted to be advanced distally past the distal, blunt tip, occluder end and fixed to sacral bone enabling retention of the tubular member in axial alignment with the visualized, anterior axial instrumentation/fusion line, whereby the attached tubular member provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line;  
       a dilator adapted to dilate tissue surrounding the elongated tubular member to form an enlarged percutaneous tract that is aligned with the visualized, anterior axial instrumentation/fusion line; and  
       an enlarged diameter tubular enlarged diameter anterior tract sheath having a tract sheath lumen extending between enlarged diameter anterior tract sheath proximal and distal ends and an enlarged diameter anterior tract sheath distal fixation mechanism adapted to attach said enlarged diameter anterior tract sheath to sacral bone, said enlarged diameter anterior tract sheath sized in sheath lumen diameter to be advanced through the dilated presacral space to position said enlarged diameter anterior tract sheath distal end against the anterior sacrum with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized anterior axial instrumentation/fusion line, whereupon said enlarged diameter anterior tract sheath distal fixation mechanism is operable to attach said enlarged diameter anterior tract sheath to sacral bone with the enlarged diameter anterior tract sheath lumen aligned axially with the visualized, anterior axial instrumentation/fusion line;  
       wherein the enlarged diameter anterior tract sheath fixation mechanism comprises distal screw threads encircling the enlarged diameter anterior tract sheath distal end adapted to be screwed into bone at the anterior target point by rotating the enlarge diameter anterior tract sheath body in a proximal section extending from the skin incision to screw the distal screw threads into sacral bone.  
     
     
       120. The system of  claim 119 , wherein the dilator further comprises: 
       a dilatation balloon catheter having an expandable balloon and a balloon catheter lumen extending between balloon catheter proximal and distal ends, the dilatation balloon catheter adapted to be advanced over the tubular member within the catheter lumen to locate the deflated balloon of the dilatation balloon catheter extending through presacral space; and  
       means for expanding the deflated balloon to an expanded balloon diameter to dilate the presacral tissue between the anterior target point and the skin incision and deflating and withdrawing the balloon catheter from the enlarged diameter anterior tract sheath lumen, whereby the enlarged diameter anterior tract sheath lumen provides the anterior, presacral, percutaneous tract through the patient's presacral space.  
     
     
       121. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       an elongated occluder extending between a proximal occluder end and a distal, blunt-tip, occluder end;  
       a tubular member having a tubular member body extending between a tubular member body proximal end and a tubular member body distal end enclosing a tubular member lumen and having a tubular member distal fixation mechanism at the tubular member body distal end, the occluder adapted and sized to be inserted through the tubular member lumen to form a guide assembly with the distal blunt-tip occluder end projecting distally from the tubular member distal fixation mechanism thereby providing a guide assembly distal end with the tubular member distal fixation mechanism retracted to prevent catching on body tissue, the guide assembly adapted to be advanced through an incision made through the patient's skin adjacent to the coccyx aligned with a visualized, anterior axial instrumentation/fusion line and along the anterior surface of the sacrum under visualization until the blunt tip is at an anterior target point of a selected sacral vertebrae and the tubular member body is aligned with the visualized, anterior axial instrumentation/fusion line and extends percutaneously from the proximal tubular member end located outside the incision, whereby the tubular member is adapted to be advanced distally past the distal, blunt tip, occluder end and fixed to sacral bone enabling retention of the tubular member in axial alignment with the visualized, anterior axial instrumentation/fusion line, whereby the attached tubular member provides a percutaneous tract for over the wire passage extending from the skin incision to the anterior target point and aligned with the visualized anterior axial instrumentation/fusion line; and  
       a dilator adapted to dilate tissue surrounding the elongated tubular member to form an enlarged percutaneous tract that is aligned with the visualized, anterior axial instrumentation/fusion line;  
       wherein the dilator further comprises:  
       a dilatation balloon catheter having an expandable balloon and a balloon catheter lumen extending between balloon catheter proximal and distal ends, the dilatation balloon catheter adapted to be advanced over the tubular member within the catheter lumen to locate the deflated balloon of the dilatation balloon catheter extending through presacral space; and  
       means for expanding the deflated balloon to an expanded balloon diameter to dilate the presacral tissue between the anterior target point and the skin incision and deflating and withdrawing the balloon catheter from the enlarged diameter anterior tract sheath lumen, whereby the enlarged diameter anterior tract sheath lumen provides the anterior, presacral, percutaneous tract through the patient's presacral space.  
     
     
       122. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs and boring a trans-sacral axial instrumentation/fusion bore through the sacrum and into at least one vertebrae and any intervertebral disc in alignment with a visualized, trans-sacral axial instrumentation/fusion line, the system comprising: 
       a guide member extending between guide member proximal and distal ends that is adapted to be inserted through the skin incision and advanced through presacral space along the anterior surface of the sacrum to the anterior target point and axially aligned with a visualized, trans-sacral axial fusion/instrumentation line extending in said axial aspect through a series of adjacent vertebral bodies;  
       an anterior percutaneous tract forming member extending between tract forming member proximal and distal ends adapted to be inserted through the skin incision and advanced through presacral space along said guide member; and  
       a boring tool adapted to be advanced to said anterior target point through said percutaneous tract to bore a trans-sacral axial instrumentation/fusion bore through the sacrum and into at least one vertebrae and any intervertebral disc in alignment with said visualized, trans-sacral axial instrumentation/fusion line.  
     
     
       123. The surgical operating system of  claim 122 , wherein said guide member further comprises a distal fixation mechanism adapted to be fixed to the anterior surface of the sacrum at the anterior target point. 
     
     
       124. The surgical operating system of  claim 122 , wherein said anterior percutaneous tract forming member further comprises a distal fixation mechanism adapted to be fixed to the anterior surface of the sacrum at the anterior target point. 
     
     
       125. The surgical operating system of  claim 122 , wherein said guide member further comprises a guide assembly that further comprises: 
       an elongated tubular member having a tubular member body enclosing a tubular member lumen extending between a tubular member proximal end and a tubular member distal end; and  
       an elongated occluder having an occluder body extending between an occluder proximal end and an occluder distal end that is adapted to be inserted through the tubular member lumen; and  
       wherein at least one of the tubular member distal end and the occluder distal end is blunted and the other of the tubular member distal end and the occluder distal end further comprises a distal fixation mechanism adapted to be fixed to the anterior surface of the sacrum at the anterior target point.  
     
     
       126. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs and boring a trans-sacral axial instrumentation/fusion bore through the sacrum and into at least one vertebrae and any intervertebral disc in alignment with a visualized, trans-sacral axial instrumentation/fusion line, the system comprising: 
       a guide assembly that further comprises:  
       an elongated tubular member having a tubular member body enclosing a tubular member lumen extending between a tubular member proximal end and a tubular member distal end; and  
       an elongated occluder having an occluder body extending between an occluder proximal end and an occluder distal end that is adapted to be inserted through the tubular member lumen;  
       wherein at least one of the tubular member distal end and the occluder distal end is blunted and the other of the tubular member distal end and the occluder distal end further comprises a distal fixation mechanism adapted to be fixed to the anterior surface of the sacrum at the anterior target point,  
       whereby the one of the elongated occluder or tubular member having the distal fixation mechanism attached to the anterior surface of the sacrum at the anterior target point forms an anterior percutaneous tract through presacral space; and  
       a boring tool adapted to be advanced to said anterior target point through said percutaneous tract to bore a trans-sacral axial instrumentation/fusion bore through the sacrum and into at least one vertebrae and any intervertebral disc in alignment with said visualized, trans-sacral axial instrumentation/fusion line.  
     
     
       127. A surgical operating system for forming a percutaneous pathway from a skin incision generally axially aligned with a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect, the vertebrae separated by intact or damaged spinal discs, the system comprising: 
       a guide assembly that further comprises:  
       an elongated tubular member having a tubular member body enclosing a tubular member lumen extending between a tubular member proximal end and a tubular member distal end; and  
       an elongated occluder having an occluder body extending between an occluder proximal end and an occluder distal end that is adapted to be inserted through the tubular member lumen;  
       wherein at least one of the tubular member distal end and the occluder distal end is blunted and the other of the tubular member distal end and the occluder distal end further comprises a distal fixation mechanism adapted to be fixed to the anterior surface of the sacrum at the anterior target point,  
       whereby the one of the elongated occluder or tubular member having the distal fixation mechanism attached to the anterior surface of the sacrum at the anterior target point forms an anterior percutaneous tract through presacral space.